Detail sander

ABSTRACT

An oscillating tool for sanding a surface has a body (12) defining an internal cavity (14) and a motor (20) located therein The motor has a motor shaft (22) oriented in parallel with the body. A crank (24) is affixed to the motor which has a crank pin (26) projecting therefrom. A lever arm (34) is pivotably affixed to the body for rotation about a pivot axis generally perpendicular to the motor shaft. The lever arm cooperates with the crank pin to cause the lever arm to cyclically pivot back and forth. A pad support (18) is adapted to receive a work member (19). The planar pad support is affixed to the lever arm at a location spaced apart from the pivot axis and oscillated therewith. The pad support has a substantially 90 degree forward corner (110) formed by a pair or facet edges and a pair of outwardly inclined straight side edges (116, 118).

TECHNICAL FIELD

This invention relates to an oscillating tool and more particularly to amechanism for oscillatingly driving a sanding tool about a remotelylocated pivot axis.

BACKGROUND ART

Detail sanders are used for performing specific finishing tasks such assanding edges adjacent internal walls. To perform such tasks, the toolsutilized must be able to have controlled finite movement in a confinedarea so as to fine sand the desired area without damaging the surfaceupon which the work is being performed. Various approaches have beentaken to perform the difficult task of sanding these internal cornersand other hard to reach areas which require fine sanding or abrasion.

Initially, hand sanders were utilized to perform these tasks. U.S. Pat.No. 4,825,597 to Matechuk discloses a corner hand sander which has asanding surface in the form of a prism having an angle of 90 degrees.Electrically operated tools replaced hand corner sanders similar to theone disclosed above. A common feature among the electrically drivensanders or grinders is that all utilize pivotal or oscillating motion orrotational motion to drive the abrasive pad.

U.S. Pat. No. 4,920,702 to Kloss et al., discloses a portable grinderrelying upon pivotal motion by oscillating about a fixed axis whichintersects the grinding tool in a central region. The abrasive pad hasexposed side edges which are convex in shape such that side edges meetto form at least one corner region having an angle of less than 90degrees. A similar pear-shaped oscillating abrasive pad for reachinginto square corners is described in UK patent 2141620 to Brown.

U.S. Pat. No. 3,190,045 to Zuzelo, discloses an abrasive tool definingan equilateral triangle having three convex sides such that each side iscurved in the form of an arc centered on the opposing vertex. The toolrotates about a central axis and has 3 corners which form approximately90° angles for grinding or polishing into square corners.

An alternative approach is disclosed in U.S. Pat. No. 3,160,995 toDamuski, Jr. in which a corner sander has an oscillating orreciprocating sector-shaped abrasive pad. The pad contains a pair ofradiant side edges which move through a total angle just slightly lessthan the 90 degree angle of the corner to be finished.

U.S. Pat. No. 2,350,098 to Decker discloses an oscillating sander whichhas a sanding head which has an abrasive pad which is driven about anangle transverse to and at a right angle with the motor drive shaft.

U.S. Pat. No. 2,734,139 to Murphy discloses an electrically operatederaser which utilizes spaced magnetic poles and an adjacent armaturemovable therebetween for actuating the tool. A drive pin is connected tothe armature and a fulcrum to shiftably move the eraser. In thisconfiguration, the armature reciprocates between the two poles by meansfor magnetizing the poles.

The present invention incorporates many of the known benefits of detailsanders while improving the mechanism utilized for oscillatingly drivingthe abrasive pads about a pivot axis.

SUMMARY OF THE INVENTION

A detail sander is provided which has a body defining an internalcavity. A motor is located within the cavity and has a rotatable motorshaft. A crank is provided which is affixed to the motor shaft such thatthe crank has a crank pin projecting therefrom. A lever arm is providedwhich is pivotally affixed to the body for rotation about a pivot axisgenerally perpendicular to the motor shaft. The lever arm cooperateswith the crank pin to cause the lever arm to cyclically pivot back andforth in response to rotation of the motor shaft. An abrasive padsupport is affixed to the lever arm at a location spaced apart from thepivot axis and oscillates therewith for sanding a surface.

Also provided is a detail sander having a body which defines an internalcavity. A motor is located within the cavity and has a rotatable shaftaffixed thereto. A crank is affixed to the motor shaft such that thecrank has a crank pin projecting therefrom. A lever arm is providedwhich is axially aligned with the motor shaft. The lever arm has a firstend, a second end and a central portion. The first end cooperates withthe crank. The central portion is pivotally affixed to the body enablingthe lever arm to cyclically pivot back and forth in response to rotationof the motor shaft. An abrasive pad support is affixed to the second endof the lever arm and oscillates therewith for sanding the surface.

Further, a detail sander is provided which has a body defining aninternal cavity. A motor is located within a cavity and has a rotatablemotor shaft affixed thereto. A crank is affixed to the motor shaft suchthat the crank has a crank pin projecting therefrom. A lever arm isprovided which is axially aligned with the motor shaft. The lever armhas a first end, a second end, and a central portion. The first endcooperates with the crank. The central portion is pivotally affixed tothe body to enable the lever arm to cyclically pivot back and forth inresponse to rotation of the motor shaft. A leg is provided which isaffixed between the second end of the lever arm and an abrasive padsupport. The leg locates the pad support below the lever arm andparallel therewith. The leg and the pad support oscillate with the leverarm for sanding the surface. Accordingly, it is an object of the presentinvention to provide a detailed sander wherein the motor shaft and thelever arm are axially aligned and pivot about a pivot pin orientedgenerally perpendicular thereto.

Further, a novel sanding pad and pad support adapted to receive a planarworking member is described. The sanding pad and pad support isgenerally symmetrical about a longitudinal center line and provided witha forward most tip region having a pair of facet edges which form asubstantially 90° corner. A pair of straight side edges extendrearwardly from the tip region and are inclined outwardly 10°-30° fromthe pad support longitudinal center line.

An additional object of the present invention is to provide a lever armhaving a plurality of apertures adapted to selectively receive a pivotpin thereby enabling an oscillating range of pad support to be varied.

An advantage of the present invention is that the configuration of thedevice enables it to comfortably cooperate with the hand of an operator.

A further advantage of the present invention is that eccentric rotationof the crank pin is converted to pivotal movement of the lever arm.

Further, a novel dust collection system is provided for the pad supportwhich utilizes a series of inlet ports oriented around the periphery ofthe pad support. The input shaft of the pad is tubular and is connectedto a vacuum system via a flexible conduit.

A further advantage of the pad support of the present invention is thatthe rearwardly outwardly inclined side edges can be utilized to standalong a seam formed by two intersecting planar surfaces with minimalloading and wear of the tip regions of the work member.

A feature of the present invention is to provide the pad support havinga planar surface parallel to and offset from the motor shaft asufficient distance to provide clearance between the body and asubstantially flat surface to be sanded which is in coplanar relationwith the pad support.

An additional feature of the present invention is that the 90° tipregion pad of the support provides for increased durability and a longersandpaper life when the detail sander is used to sand a corner formed bytwo substantially perpendicular walls which abut the work surface.

An additional feature of the present invention is that the pad supportis generally parallel to the lever arm and the planar surface of the padsupport is generally perpendicular to the pivot pin such that theoscillating of the pad support occurs within a plane defined by the padsupport.

A further feature of the present invention is that the pivot axis isspaced apart from the pad support resulting in oscillating movement ofthe pad support in response to movement of the lever arm.

The above objects, features and advantages of the present invention arereadily apparent from the following detailed description of theinvention when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a schematic representation showing themajor elements in accordance with the present invention;

FIG. 2 is a perspective view of the device partially broken away showingthe internal elements of the present invention;

FIG. 3 is a plan view of the device partially broken away showing theinternal elements of the present invention;

FIG. 4 is a partial plan view of the crank pin cooperating with thefirst end of the lever arm;

FIG. 5 is an end view taken along line 5--5 of FIG. 4;

FIG. 6 is a plan view of the crank pin and the lever arm pivoting abouta pivot axis located toward the second end of the lever arm;

FIG. 7 is a view similar to that shown in FIG. 6 showing the increasedoscillating range of the device pivoting about a pivot axis locatedtoward the first end of the lever arm;

FIG. 8 is an exploded view of the invention;

FIG. 9 is a perspective view of an alternative leg attachment;

FIG. 10 is a perspective view of an alternative embodiment of thepresent invention;

FIG. 11 is a plan view illustrating the peripheral outline of a secondpad support embodiment;

FIG. 12 is a fragmentary view of a drawer being sanded utilizing thedevice of the present invention;

FIG. 13a is a plan view illustrating the peripheral outline of a thirdpad support embodiment;

FIG. 13b is an exploded perspective view of an alternative pad supportprovided With a dust collection system.

FIG. 14 is an alternative embodiment for the detail sander having ancentrally pivoted pad and a dust collection system;

FIG. 15 is a cross-sectional view taken along line 15--15 of FIG. 14;

FIG. 16 is a plan view of the pad support taken along line 16--16 ofFIG. 14;

FIG. 17 is a schematic illustration of yet another embodiment of theinvention; and

FIG. 18a-18c are schematic illustrations of a drive motor circuit.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiment shown in FIGS. 1 through 8 illustrates a detailsander 10, which is utilized for sanding inside corners and other hardto reach locations. The sander 10 has a body 12, including a gripportion 13 for cooperation with the hand of an operator. The body 12forms an internal cavity 14. A leg 16 is attached to the body 12 andcooperates therewith. Pad support 18 is attached to the leg 16 forsupporting a work member such as sandpaper pad 19. In this embodiment,the member is intended to be sandpaper pad 19 or a similar abrasivematerial is removably attached to pad support 18 by a thin layer ofadhesive.

As shown in FIGS. 2 and 3, the body 12 of the sander 10 has a generallylongitudinal orientation such that the grip portion 13 is configured tofit comfortably in the hand of an operator. A motor 20 has a generallysimilar orientation as the body 12. A motor shaft 22 projects outwardfrom the motor 20 along the longitudinal axis of the motor 20 and isrotatably driven by the motor 20. A crank 24 is affixed to the motorshaft 22 so as to be driven by the motor shaft 22. As shown in FIG. 3,the crank 24 is affixed to the motor shaft 22 such that the motor shaft22 passes through the crank 24. A crank pin 26 is generally parallel toand radially off set from the motor shaft 22. The crank pin 26 isaffixed to the crank 24 and extends outwardly therefrom.

A bearing 28, shown in FIGS. 2 and 3, substantially surround the crank24. The bearing 28 includes an inner race 30 and an outer race 32 and aseries of balls or rollers for transmitting radial loads occurring frommovement of the crank pin 26 to the body 12. The bearings 28 are affixedto the body 12 to ensure that they are maintained in position andeffectively transmit any radial loads received.

A lever arm 34 has a first end 36, a second end 38 and a central region40. A screw hole 41 is located in the second end 38 to receive a legscrew 43 for securing the leg 16 to the lever arm 34. As shown in FIG.8, the leg 16 has a rectangular cavity 45 which is adapted to receivethe second end 38 of the lever arm 34. The central region 40 of thelever arm 34 defines at least one aperture 42. In the preferredembodiment (shown in FIGS. 1, 5 and 6), the central region 40 defines apair of apertures 42a and 42b. The aperture 42 is adapted to receive apivot pin 44 about which the lever arm 34 pivots in response to rotationof the motor shaft 22.

As schematically represented in FIG. 1, the motor shaft 22, the crank24, and the lever arm 34 are generally longitudinally aligned. Thisalignment serves at least two purposes. First, the profile of the sander10 is able to be smaller, i.e. have a lower silhouette, which allows thesander 10 to fit more comfortably into the hand of the operator.Secondly, this alignment allows for a very simple mechanical arrangementfor oscillating or cyclically pivoting the support pad 18 back andforth.

As shown in FIGS. 2, 3 and 8, a frame 46 surrounds the lever arm 34, thecrank 24, the crank pin 26 and the motor shaft 22. The frame 46 supportsthe pivot pin 44 and is anchored to the motor 20 by conventional meanssuch as screws 28, or the like. The purpose of the frame 46 is toprovide internal strength and rigidity to the tool 10 so that the motorshaft 22, the crank 24, the crank pin 26 and the lever arm 34 caneffectively work as a unit. This is accomplished by the frame absorbingforces resulting from the interaction of these components, therebyminimizing the load exerted on body 12.

The frame 46 has a first portion 50 which is generally cylindrical inshape. The first portion supports bearing 28 and has a flange 52 locatedat one end thereof which defines a pair of holes 54 for receiving screws48. The flange 52 is configured to cooperate with the motor 20 forattachment thereto. A second portion 56 of the frame 46 is generallyrectangular in shape. The second portion 56 is adapted to receive thelever arm 34. Pin holes 58a and 58b correspond to apertures 42a and 42bin the lever arm 34 to receive the pivot pin 44.

As may be seen in FIG. 1, the location of the pivot (in this embodimentthe pivot pin 44) is generally perpendicular to the lever arm 34. Thepivot pin 44 is mounted to the body so as to be fixed relative to thelever arm 34. The pivot pin 44 allows the lever arm 34 and the supportpad 18 to oscillate in unison, in a parallel plane, about the pivot pin44.

As shown in FIGS. 4-7, the first end 36 of the lever arm 34 has a slot60 formed therein. In this embodiment, the slot 60 has a U-shapedconfiguration. The first end 36 has gradually tapered opposed internalsurfaces 62 which are closer together or relatively smaller at a closedend 64 of the slot 60. The first end 36 is adapted to cooperate with thecrank pin 26 of the crank 24. As may be seen in FIGS. 5, 6, and 7, theeccentric rotation of the crank 24 causes the crank pin 26 toalternatively contact each one of the internal surfaces 62 during acomplete cycle of the crank 24. In a complete cycle, the crank 24simultaneously undergoes up and down movement within the slot 60 of thelever arm 34 and eccentric rotation so as alternatively contact each ofthe internal surfaces 62 of the slot 60. High temperature grease such assulfurized molybdenum is used at this location and at the pivot pin 44level arm 34 interface.

During a complete rotational cycle of the crank pin 26, (as shown inFIGS. 6 and 7), the crank pin 26, alternatively contacts each of theinternal surfaces 62 of the U-shaped slot 60. This contact causestangential pressure to be exerted onto the lever arm 34. In response tothis tangential pressure, the lever arm 34 pivots about the pivot pin 44in a direction corresponding to the direction of the pressure beingexerted. As the rotational cycle continues, the crank pin 26 willcontact both of the internal surfaces 48 which results in the lever arm34 oscillating back and forth about the pivot pin 44. The cooperation ofthe first end 36 and the crank pin 26 converts eccentric rotation topivotal motion of the lever arm 34.

It is this conversion of eccentric rotation of the crank pin 26 topivotal movement of the lever arm 34 which enables the generallylongitudinal alignment of the motor shaft 22, the crank 24, and thelever arm 34 to function so effectively. In the preferred embodimentshown in FIGS. 1, 6 and 7, the lever arm 34 has a pair of apertures 42aand 42b, respectively. As may be seen in FIGS. 6 and 7, the ability ofthe lever arm 34 to receive the pivot pin 44 in more than one locationallows the range of oscillation (represented in FIGS. 6 and 7 as X andX', respectively) to be varied to accommodate the type of work to beperformed. Specifically, FIG. 6 shows the pivot pin 44 seated withinaperture 42b. Aperture 42b is located closer to the second end 38 thanis aperture 42a. The result is that the range of oscillation X inresponse to movement of the motor shaft 22 is smaller. By moving thepivot pin 44 to the aperture 42a, the range of oscillation X' isrelatively increased, as may be seen in FIG. 7.

As shown in FIGS. 2, 8 and 9, the shape of the leg 16 is offset suchthat it projects outward from the body 12 and generally perpendicularthereto. The result is that the pad support 18 is located a distancefrom and below the body 12. The pad support 18 is affixed to the leg 16such that it is parallel with a foot 66. The foot 66 is integrallyformed with the leg 16 and is generally parallel with the body 12. Thepad support 18 is affixed to the foot 66 so as to be contiguoustherewith. The result of the configuration of the leg 16, the foot 66and the support pad 18 relative to the body 12 is that the planarsurface of the support pad 18 is sufficiently spaced from the body 12 sothat when sanding a surface which is in coplanar relationship, the handof the operator comfortably fits about the body 12. In operation, thepad support 18 oscillates within a plane defined by the pad support 18.

The pad support 18 shown in FIGS. 1-3, has a generally triangularconfiguration. However, it is possible that the configuration of the padsupport 18 be varied substantially so long as the planar surface ismaintained generally parallel to the body 12, while still obtaining thedesired features and functions of this invention.

An alternative leg embodiment is shown in FIG. 9. In this embodiment, ascraper blade 68 is affixed to foot 70 by screws 72. The scraper blade68 can be utilized for removing wallpaper or the like. Foot 70 can beinstalled on the end of lever arm 34 in place of leg 16.

An alternative embodiment of the invention is illustrated in FIG. 10.Detail sander 80 operates in a similar fashion to sanding tool 10described in FIGS. 1-8. Rather than the centrally pivoting the leverarm, lever 82 is pivoted upon pin 84. Pad support assembly 86 is affixedto the opposite end of lever 82. In the central region of lever 82,flange 88 is provided in which is formed an elongated slot 90 forreceiving crank pin 92 formed on crank 94. Motor 96 rotates the crankpin 92 in a manner similar to the sanding tool described previously.Lever 82 is preferably provided with a plurality of holes so that thepivot pin 84 can be alternatively positioned at different locations ofvarying the stroke of the pad.

An alternative pad support assembly 100 is shown in FIG. 11. Pad supportassembly 100 is an alternative to the equilateral triangle design asshown previously in FIGS. 1, 3, 8 and 10. Pad support assembly 100 ismade up of a rigid plastic leg 102, a rigid plastic foot portion 104 andan elastic planar pad support member (not shown) which is affixed to theunderside of foot portion 104 in the same manner pad support 18 isaffixed to foot 66 illustrated in FIG. 8.

The outer periphery of pad support assembly 100 forms a nine sidedpolygon. The pad support is symmetrically aligned along longitudinalcenter line 106. Longitudinal center line 106 is generally aligned withthe longitudinal axis of the detail sander deviating slightly therefromas the lever and the pad support pivot about pivot point 108. Theforward most portion of the pad support forms a tip region 110 definedby a pair of facet edges 112 and 114 oriented at angle α to one another.Preferably, the angle α is substantially 90°. Most preferably, angle αwill fall between 90° and 90°+ the angle of oscillation of the lever padsupport assembly about a pivot point 108. In the embodiment illustrated,in FIG. 11, α is a nominal 91°+ or - one degree manufacturing tolerance.Pad support 100 additionally has a pair of straight side edges 116 and118, each extending rearwardly from facet edges 112 and 114,respectively, outwardly inclined from center line 106 an angle rangingfrom 10 to 30 degrees. In the embodiment illustrated, which ispreferable in the majority of instances, angle β is equal to 30°.

In order to maximize the amount of usage from a single sheet ofsandpaper, it is very desirable to have a pad support which has threecorners as illustrated in FIG. 11. The right and left corners 120 and122 are symmetrical with corner 110 and are defined by facet edges 124,126, 128 and 130 as illustrated. Extending between facet edges 126 and128 is a rear edge 132 which extends perpendicular to center line 106.This three corner symmetrical design enables the sandpaper having becomeworn at the forward most tip to be removed, rotated 120° and reinstalledin order to utilize all three corners.

It should be appreciated that the forward most tip of the sandpaperwears the quickest. The utilization of a substantially 90° corner asopposed to a 60° corner illustrated in the equilateral triangle designdescribed previously, significantly increases sandpaper life. The reasonfor this gain in life is two-fold. First, angle α being greater, thecorner is less sharp and has more sandpaper area and is less susceptibleto damage when sanding with the corner. Secondly, the fact that the tipis no longer aligned with the side edges minimizes were in the cornerregions, when the sander is being worked along the seam formed by twointersecting planar surfaces. When using the sander to sand along a seamformed by two planar surfaces, the user typically rocks the sanderslightly to concentrate the sanding load along the edge of the padsupport. Since the pad support is somewhat elastic, there wouldtypically be very little normal force exerted on the workpiece by corner120 when side edge 116 is being utilized. This offset corner designresults in very little wear occurring in the corners when the side edges116 and 118 are being used.

FIG. 12 illustrates the nine sided polygon pad support assembly 100affixed to a sander 134. The sander is being used to sand a seam 136formed in a drawer 138 between drawer bottom 140 and drawer side 142.Pad support 100 oscillates side to side about pivot 108 between theextreme right position shown in solid outline and the extreme leftposition shown dotted outline. For purposes of illustration, themagnitude of the movement is exaggerated slightly. In the preferredembodiment of the angle of oscillation is only 1 to 2 degrees. Unlikeprior art sanders of Kloss, Brown or Zuzelo which rotate about a centralpivot point, the present invention is a pivot point 108 which is offsetoutside of the outer periphery of the pad support in plain view. Thiscauses the pad support to oscillate back and forth, side to sideenabling a straight side edge to be effectively used. The straight sideedge is particularly important when the user tries to rock the sanderslightly in order to concentrate the sanding effort along the regionimmediately adjacent to the seam 136.

When sanding the corner region 143 of the drawer, it is necessary forthe tip of pad support 100 to get completely into the corner which isformed by the intersection of the drawer bottom 140, side wall 142 andrear wall 144 oriented 90° to one another. The forward most corner 110of the pad support is used when sanding corner region 143. Thelongitudinal axis 146 of the sander will be oriented 45° from side wall142 and back wall 144 to facilitate the insertion of sanding Dad cornerregion 110 completely into corner 143. As described previously, thesander will be rocked slightly in order to concentrate the load exertedby the sandpaper or other abrasive material affixed to the pad supportin the region to be sanded. When sanding seam 148 formed at the junctionof drawer bottom 140 and back panel 144, the side edge 118 of the padsupport will be utilized in a manner described previously.

A third pad support assembly embodiment 150 is illustrated in FIG. 13a.Pad support 150 unlike the equilateral triangle embodiment and the ninesided polygon embodiment described previously does not have a pluralityof corners which facilitate the removal and rotation of sandpaper or toa different position. Like pad support 100, the third pad supportembodiment 150 is provided with a corner 152 formed by a pair of facetedges 154 and forming an angle α. Preferably angle α is approximately90° or slightly larger. Pad support assembly 150 is symmetrical aboutcenter line 158 and is provided with a pair of straight side edges 160and 162 which extend rearwardly, outwardly at an angle θ relative tocenter line 158. In the embodiment illustrated, θ is approximately at10° which results in the pad support having a much narrow width. Padsupport 150 is therefore useful in situations where it is necessary toreach into tight places such as between spindles forming the back of aWindsor chair. Corner region 152 is offset significantly from the linedefining side edges 160 and 162, and one, therefore, can utilize theseside edges with minimal wear of the forward most corner portion of theabrasive pad.

An alternative pad support and leg assembly 250 illustrated in FIG. 13b,is designed to provide a dust collection feature for the detail sander10 previously illustrated. Pad support and leg assembly 250 is made upof a leg 252 which attaches to detail sander 10 in the same manner asleg 16 previously described. Leg 252, however is provided with aninternal dust collection passageway which extends axially communicatingwith pad support foot portion 254 and radially via port 256. Port 256 isadapted to be coupled to flexible rubber conduit 258. Conduit 258 canflex enabling leg 252 to oscillate relative to rigid dust collectionconduit 260.

The lower tubular portion of leg 252 is provided with tapered pipeexternal threads and a series of circumferentially spaced apart axiallyextending slints 262. The internal cavity formed within leg 252 ishexagon in shape sized to telescopically cooperate with shaft 168 offoot 254. Knob 170 is provided with cooperating tapered pipe threadsenabling the leg 252 and foot 258 to be removably attachable to oneanother and six alternative orientations. This enables the foot to beremoved reoriented when one corner of the sanding paper is worn as wellas enabling alternative implements to be installed, such as the scraperpreviously described with reference to FIG. 9.

A foot portion 254 is a rather simple structure which can be made usinga plastic ejection molding process. The underside of the foot isprovided with a series of channels which extend from a central axialpassageway 172 to the outer periphery of the foot to define a series ofapertures 174 when the flexible pad support 176 is applied to the footunderside. Pad support cushion member 176 is formed of foam rubber orthe like which provides a uniform flat surface upon which an abrasivepad such as self-adhesive sandpaper 178 can be attached. It should benoted that there are no openings provided in the sandpaper for dustcollection as all of the dust collection takes place around the padouter periphery. This design enables the same sandpaper used on theprevious embodiments of the invention to be utilized; a sander equippedwith a dust collection apparatus.

An alternative sander 180 is illustrated in FIGS. 14-16. The sander isprovided dust collection system as well as a centrally pivoted pad.Sander 180 is similar to the embodiments described previously in that itutilizes an electric motor driven eccentric 182 for oscillating a lever184 which is generally aligned with the motor shaft. Drive shaft 186 isaffixed to lever 184 in a secure manner in order to cause drive shaft186 to rotationally oscillate foot 188 which is connected to drive shaft186 via a connector 190. Connector 190 which is provided with aninternal axial passageway 192 and radially extending a port coupled toflexible connector 194. The dust collection system for sander 180functions similar to that previously described with reference to FIG.13b. One difference, however is the dust collection conduit 196 isintegrally formed as part of the housing as illustrated in thecross-sectional sectional view of FIG. 15. One end of the conduit 196 isconnected to the flexible connector 194 and the opposite end is enlargedto telescopically receive a flexible vacuum hose. As described withreference to the FIG. 14 dust collection system, flexible connector 194enables foot 188 and drive shaft 186 to rotate through its angle ofoscillation while maintaining a vacuum tight connection.

As previously indicated with reference to FIG. 13b, the outer side offoot 188 is provided with a series of channels 198 which communicateswith the central axial passageway which extends therethrough. Thechannels are design such that adequate support is always maintained forthe pad support cushion member which is bonded thereto.

Yet, another alternative embodiment of the present invention isillustrated in sander 200 of FIG. 17. Sander 200 differs from theprevious embodiment in that it is powered by battery 210. The battery isoriented in its housing of the sanding pad. Sander 200 has a narrowcentral waist portion 212 in which the motor is oriented. Preferably,the central portion 212 of the housing is generally circular in shapehaving a diameter of between 2" to 3" forming a convenient grip. Motor Mis a conventional permanent magnet DC motor having a no load outputspeed of 8,000 rpm and a output speed of approximately 4,000 rpm at peaktorque. In order to maintain a small waist diameter of housing portion212, preferably motor M has a diameter of less than 2" and mostpreferably, 1.5". It has been determined that a motor having an outputof 3 oz. in or 216 g-CM and provides adequate power in normal operatingconditions.

Motor M utilized in the FIG. 17 embodiment is of the same type utilizedin the corded version illustrated with reference to FIGS. 1-8. Whenmotor M is used on a corded 120 volt sander, a pulse transformerrectifier 214 as illustrated in FIG. 18A is provided between motor M and120 volt input terminal 216. Conventional switch 218 is provided in thecircuit in order to regulate the on/off operation of motor M.

FIG. 18B is an electrical schematic used in conjunction with sander 200.Motor M is powered by battery 230. Battery 230 can be of a conventionallead acid type or most preferably, the nickel cadmium type.

FIG. 18C illustrates an alternative motor circuit for use in 240 voltapplications. A conventional universal motor M' is utilizes as opposedto a permanent magnet DC motor. Although a conventional universal motoris more expensive and somewhat larger than a DC permanent magnet motor,it is unnecessary to meet European motor standards.

While the best mode for carrying out the invention has been described indetail, those familiar to the art to which this invention relates willrecognize various alternative designs and embodiments for practicing theinvention as defined by the following claims.

What is claimed is:
 1. A detail sander comprising:a body having aninternal cavity; a motor located within said cavity and having a motorshaft rotatable about a motor axis; a crank affixed to said motor shaft,said crank having a crank pin projecting therefrom parallel to andradially spaced from the motor shaft; a lever arm pivotally affixedrelative to said body for rotation about a pivot axis generallyperpendicular to said motor shaft, said lever arm extending generallycoaxially with said motor axis and having a first end cooperating withsaid crank pin to cause said lever arm to cyclically pivot, and a secondend which moves transversely from side to side in response to rotationof said motor shaft; and a pad support having a planar surface adaptedto receive a work member, said pad support affixed to said lever armsecond end.
 2. The sander of claim 1 further comprising a rigid frameanchored to said motor for pivotal supporting said lever arm relativethereto, said frame being affixed to said body.
 3. The sander of claim 1wherein said lever arm has an aperture adapted to receive said crank pintherein and convert the rotary motion of said motor into oscillatingpivotal motion of said lever arm.
 4. The sander of claim 1 wherein saidbody has grip portion adapted to cooperate comfortably with a hand of anoperator.
 5. The sander of claim 1 wherein said work member comprises anabrasive material.
 6. The sander of claim 1 wherein said work membercomprises a scraper blade.
 7. The sander of claim 2 further comprising abearing substantially surrounding said crank and cooperating with saidrigid frame to transmit loads resulting from engagement of the crank pinand the lever arm to the rigid frame and attached motor.
 8. The tool ofclaim 1 further comprising a pivot pin pivotally connecting said leverarm central region to said body.
 9. The tool of claim 8 wherein saidlever arm central portion is provided with a plurality of aperturesadapted to alternatively receive a pivot pin, thereby enabling anoscillating range of said pad support to be varied.
 10. The tool ofclaim 1 further comprising an offset leg interposedly connected betweensaid lever arm second end and said pad support, said leg locating saidpad support below said lever arm and parallel therewith, and said legand said pad support oscillating with said lever arm for sanding asurface.
 11. The tool of claim 10 wherein said pad support planarsurface is parallel to and offset from said motor shaft a sufficientdistance to provide clearance between said body and a substantially flatsurface to be sanded which is in coplanar relation to said pad support.12. The tool of claim 1 wherein said lever arm first end includes agenerally U-shaped fork adapted to receive said crank pin therein andconvert the eccentric rotary motion of said crank pin into pivotalmotion of said lever arm.
 13. The sander of claim 12 wherein saidU-shaped fork has gradually tapering opposed internal surfaces so as tobe relatively smaller at a closed end of said U-shaped configuration.14. A detail sander comprising:an elongated body having a longitudinalaxis, a forward end, a rearward end and an internal cavity therein; amotor located in said cavity and having a rotatable motor shaftgenerally aligned with said longitudinal axis; a crank affixed to saidmotor shaft, said crank having an offset crank pin projectinglongitudinally therefrom parallel to and radially spaced from the motorshaft; a lever arm pivotably cooperating with said body about a pivotaxis extending generally perpendicular to said longitudinal axis, saidlever arm having an attached output shaft aligned along said pivot axiswhich pivotally oscillates in response to the rotation of said motorshaft; a pad support having a planar surface adapted to receive a planarwork member, said pad support having a tubular shaft affixed to saidlever arm output shaft to cyclically oscillate the work member and tolocate said pad support below and parallel to said lever arm, said padsupport having an outer peripheral edge and a plurality of dustcollecting ports extending between an internal region of the tubularshaft and the pad support peripheral edge; and an elastic conduit havingone end fixed relative to said body and an opposite end fixed relativeto an in communication with said tubular shaft internal region to enablesanding dust to be collected through dust collecting ports in the padsupport by a vacuum having a suction hose affixed to said body and incommunication with said elastic conduit.
 15. The sander of claim 14wherein the tubular shaft is formed of two telescopic removablyconnectable pieces enabling the pad support orientation relative to thebody to be varied.
 16. The sander of claims 1 or 14 wherein said padsupport planar surface is symmetrical about a longitudinal center lineand has a forward most tip region having two facet edges forming asubstantially 90° corner and a pair of straight side edges extendingrearwardly from the tip region, each being outwardly inclined from thepad support center line 10°-30°.
 17. The detail sander of claim 16wherein said pad support is provided with a rearward edge extendingperpendicular to the longitudinal axis and a rear right and a rear lefttip region, each formed by a pair of facet edges oriented 90° to oneanother, wherein said edges form a nine sided polygon which issymmetrical about any line which extends through the pad center and oneof the three 90° corners formed by the tip regions.
 18. A detail sanderfor use with a collector vacuum, the detail sander comprising:anelongated body having a longitudinal axis, a forward end, a handleportion, a rearward end, an internal motor cavity, and a dust collectionconduit having an entry opening and an exit opening; a pad supporthaving an outer surface which includes a planar surface orientedsubstantially parallel to the longitudinal axis of the body and adaptedto receive a planar work member, and a shaft connected to the planarsurface, the pad support defining an internal dust collection passagewayand a plurality of collecting ports extending between the outer surfaceand the internal dust collection passageway; a motor located in theinternal motor cavity of the body and operatingly connected to the shaftof the pad support such that the pad support is driven in an oscillatingmanner; and an elastic conduit having one end fixed relative to the bodyand in communication with the entry opening of the dust collectionconduit and an opposite end fixed to and in communication with theinternal dust collection passageway of the pad support, to allowrelative movement between the entry opening and the internal dustcollection passageway during oscillation of the pad support and toenable sanding dust to be collected through the collecting ports whenthe collector vacuum is communicatingly connected to the exit opening ofthe collection conduit.
 19. The detail sander of claim 18, wherein theexit opening of the dust collection conduit is enlarged totelescopically receive the collector vacuum.
 20. The detail sander ofclaim 18, wherein the dust collection conduit and the internal motorcavity are integrally defined by the body.
 21. The detail sander ofclaim 18, wherein the handle portion of the body is provided by an outerperipheral surface of the body which extends about the internal motorcavity and the dust collection conduit.
 22. The detail sander of claim18, wherein the body in transverse cross-section defines a generallyfigure-eight shaped section provided by the generally parallel internalmotor cavity and dust collection conduit.
 23. The detail sander of claim18, wherein the body comprises right and left body portions connected toone another along a longitudinal seam so to define a generallyfigure-eight shaped section provided by the generally parallel internalmotor cavity and dust collection conduit.
 24. The detail sander of claim18, wherein the pad support is driven in a pivotally oscillating manner.25. A detail sander for use with a collector vacuum, the detail sandercomprising:a detail sander with a longitudinal axis, a forward andrearward end, a main rigid elongate body portion extending substantiallyparallel to the axis and a rigid elongate dust collection body portionextending substantially parallel to the axis; the main body portionincluding an internal motor cavity; the dust collection body portionincluding a dust collection conduit having a forward entry opening and arearward exit opening; a pad support having an outer surface whichincludes a planar surface oriented substantially parallel to thelongitudinal axis of the body and adapted to receive a planar workmember, and a shaft connected to the planar surface, the pad supportdefining an internal dust collection passageway and a plurality ofcollection ports extending between the outer surface and the internaldust collection passageway; a motor located in the internal motor cavityof the body and operatively connected to the shaft of the pad supportsuch that the pad support is driven in an oscillating manner; aconnector conduit having one end operably joined to and in communicationwith the entry opening of the dust collection conduit and the oppositeend operably joined to and in communication with the internal dustcollection passageway of the pad support, to allow relative movementbetween the entry opening and the internal dust collection passagewayduring oscillation of the pad support and enables sanding dust to becollected in collecting ports when the collector vacuum iscommunicatingly connected to exit opening of the collection conduit; andat least one of said body portions forming a handle to be gripped by theoperator of the detail sander.
 26. The detail sander of claim 25 whereinthe dust collection portion includes a forward end, a rearward end and acollector vacuum receiver extending from the rearward end, where thedust collection portion is rigidly joined substantially at its forwardand rearward ends to the main body portion.
 27. The detail sander ofclaim 26 wherein the handle portion includes both main body portion andthe dust collector portion.
 28. The detail sander of claim 27 whereinthe handle portion of the body has a generally figure-eight shapedcross-section where the upper portion of the figure-eight corresponds tothe main body portion and the lower portion of the figure-eightcorresponds to the dust collection portion and the portions areintegrally joined together.
 29. The detail sander of claim 25 whereinthe connector conduit is a discrete flexible member.